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1.
Nature ; 555(7697): 534-537, 2018 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-29539640

RESUMO

In vast areas of the ocean, the scarcity of iron controls the growth and productivity of phytoplankton. Although most dissolved iron in the marine environment is complexed with organic molecules, picomolar amounts of labile inorganic iron species (labile iron) are maintained within the euphotic zone and serve as an important source of iron for eukaryotic phytoplankton and particularly for diatoms. Genome-enabled studies of labile iron utilization by diatoms have previously revealed novel iron-responsive transcripts, including the ferric iron-concentrating protein ISIP2A, but the mechanism behind the acquisition of picomolar labile iron remains unknown. Here we show that ISIP2A is a phytotransferrin that independently and convergently evolved carbonate ion-coordinated ferric iron binding. Deletion of ISIP2A disrupts high-affinity iron uptake in the diatom Phaeodactylum tricornutum, and uptake is restored by complementation with human transferrin. ISIP2A is internalized by endocytosis, and manipulation of the seawater carbonic acid system reveals a second-order dependence on the concentrations of labile iron and carbonate ions. In P. tricornutum, the synergistic interaction of labile iron and carbonate ions occurs at environmentally relevant concentrations, revealing that carbonate availability co-limits iron uptake. Phytotransferrin sequences have a broad taxonomic distribution and are abundant in marine environmental genomic datasets, suggesting that acidification-driven declines in the concentration of seawater carbonate ions will have a negative effect on this globally important eukaryotic iron acquisition mechanism.


Assuntos
Carbonatos/metabolismo , Diatomáceas/metabolismo , Ferro/metabolismo , Transferrina/metabolismo , Organismos Aquáticos/classificação , Organismos Aquáticos/genética , Organismos Aquáticos/metabolismo , Transporte Biológico , Diatomáceas/genética , Endocitose , Evolução Molecular , Genoma/genética , Humanos , Concentração de Íons de Hidrogênio , Fitoplâncton/classificação , Fitoplâncton/genética , Fitoplâncton/metabolismo , Água do Mar/química
2.
Eur J Pediatr ; 183(4): 1703-1709, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38227054

RESUMO

The use of outpatient parenteral antimicrobial therapy (OPAT) for children has several advantages, including reduced length of hospital stay and costs. A reliable vascular access is key to delivering safe and effective pediatric OPAT. In recent years, midline catheters (MC) have been increasingly used for short-term intravenous antibiotic therapy in children. However, there are no studies investigating the use of MCs in the OPAT setting. The main aim of this paper was to evaluate the success and complications of using MCs for pediatric OPAT. This was a retrospective cohort study from a tertiary academic pediatric hospital. All MCs inserted at the hospital and used for OPAT were eligible for study inclusion. The primary objective was to describe the percentage of patients able to complete OPAT without the need for additional venous access. Forty-one MCs were included in the study. Patient mean (SD) age was 5.9 (4.9) years. In 31 cases (76%, 95% CI 62-86%), the iv therapy could be successfully completed using only the MC. Imbalances between the groups suggested unfavorable outcome for saphenous vein catheters as well as for shorter and smaller-sized catheters. Fourteen patients (34%) were subjected to a MC-related complication. Pain on injection in the MC was the most frequent complication (n = 10, 24%).    Conclusion: Midline catheters could be an alternative to central venous access for pediatric OPAT. Avoiding saphenous vein insertion and using longer and larger-sized catheters could increase MC success rate. No severe MC-related complication was found. Further randomized studies comparing different catheter types are needed. What is Known: • For selected patients, pediatric outpatient parenteral antimicrobial therapy (OPAT) is safe and provides health-economic, psychosocial, and medical advantages compared to in-hospital care. • A reliable venous access is one of the key factors to the success of OPAT, but this can be a challenge in children. What is New: • Using midline catheters, 76% of patients could complete their intended iv therapy without the need for additional venous access. Avoiding saphenous vein insertion and using longer and larger-sized catheters could increase the success rate. • Thirty-four percent of catheters were subject to some kind of complication, the most common being pain on injection in the catheter.


Assuntos
Antibacterianos , Anti-Infecciosos , Humanos , Criança , Pré-Escolar , Antibacterianos/efeitos adversos , Pacientes Ambulatoriais , Estudos Retrospectivos , Catéteres , Dor
3.
Biotechnol Bioeng ; 119(8): 2152-2166, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35470430

RESUMO

In this study, we demonstrated the first, to our knowledge, integrated continuous bioprocess (ICB) designed for the production of acid-sensitive monoclonal antibodies, prone to aggregate at low pH, on pilot scale. A high cell density perfusion culture, stably maintained at 100 × 106 cells/ml, was integrated with the downstream process, consisting of a capture step with the recently developed Protein A ligand, ZCa ; a solvent/detergent-based virus inactivation; and two ion-exchange chromatography steps. The use of a mild pH in the downstream process makes this ICB suitable for the purification of acid-sensitive monoclonal antibodies. Integration and automation of the downstream process were achieved using the Orbit software, and the same equipment and control system were used in initial small-scale trials and the pilot-scale downstream process. High recovery yields of around 90% and a productivity close to 1 g purified antibody/L/day were achieved, with a stable glycosylation pattern and efficient removal of impurities, such as host cell proteins and DNA. Finally, negligible levels of antibody aggregates were detected owing to the mild conditions used throughout the process. The present work paves the way for future industrial-scale integrated continuous biomanufacturing of all types of antibodies, regardless of acid stability.


Assuntos
Anticorpos Monoclonais , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/química , Reatores Biológicos , Células CHO , Cricetinae , Cricetulus , Proteína Estafilocócica A/química
4.
Anesth Analg ; 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36729761

RESUMO

BACKGROUND: Midline catheters are peripheral intravenous (IV) catheters in which the tip of the catheter does not reach the central circulation. In children, the use of midline catheters could lead to decreased complications from central venous catheters. To validate the safety of midline catheter use in children, we aimed to describe the complications and dwell time of pediatric midline catheters. The primary outcome was the incidence of catheter-related venous thromboembolism (VTE). METHODS: We conducted an observational, prospective study including consecutive patients at a tertiary multidisciplinary pediatric hospital. One hundred pediatric midline catheters were followed for thrombotic, infectious, and mechanical complications. After catheter removal, Doppler ultrasonography was performed to detect asymptomatic VTE. RESULTS: The mean age was 6.0 years (standard deviation [SD], 4.7), and median catheter dwell time was 6 (4-8) days. Most midline catheters were inserted in arm veins, most commonly in the basilic vein (56%). Catheter-related VTE was diagnosed in 30 (30%; 95% confidence interval [CI], 21%-40%) cases, corresponding to an incidence rate of 39 (95% CI, 26-55) cases per 1000 catheter days. Eight of 14 saphenous vein catheters were complicated by VTE compared to 22 of 86 arm vein catheters, suggesting an imbalance in favor of arm vein insertion site. Two patients needed anticoagulation therapy due to catheter-related VTE. Thirty (30%) catheters were removed unintentionally or due to complications, 22 of these needed additional IV access to complete the intended therapy. No catheter-related bloodstream infection (95% CI, 0%-4%) occurred. Mechanical complications occurred in 33 (33%; 95% CI, 24%-43%) midline catheters. CONCLUSIONS: In children, thrombotic and mechanical complications of midline catheters are common, but only few VTEs are severe enough to warrant anticoagulation therapy. Systemic infectious complications are rare. Seventy-eight percent of patients did not need additional venous access to complete short-term IV therapy. Considering the rate of clinically relevant complications and the catheter dwell time, pediatric midline catheters could be an alternative to central venous access for short-term (5-10 days) IV therapy.

5.
Eur J Pediatr ; 181(8): 3031-3038, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35652985

RESUMO

The risk for venous thromboembolism (VTE) is considered to be low in the general paediatric intensive care unit (PICU) population, and pharmacological thromboprophylaxis is not routinely used. PICU patients considered at high-risk of VTE could possibly benefit from pharmacological thromboprophylaxis, but the incidence of VTE in this group of patients is unclear. This was an observational, prospective study at a tertiary multi-disciplinary paediatric hospital. We used comprehensive ultrasonography screening for VTE in critically ill children with multiple risk factors for VTE. Patients admitted to PICU ≥ 72 h and with ≥ two risk factors for VTE were included. Patients receiving pharmacological thromboprophylaxis during their entire PICU stay were excluded. The primary outcome of the study was VTEs not related to the use of a CVC. Ultrasonography screening of the great veins was performed at PICU discharge. Seventy patients with median (interquartile range) 3 (2-4) risk factors for VTE were evaluated. Median age was 0.3 years (0.03-4.3) and median PICU length of stay 9 days (5-17). Regarding the primary outcome, no symptomatic VTEs occurred and no asymptomatic VTEs were found on ultrasonography screening, resulting in an incidence of VTEs not related to a vascular catheter of 0% (95% CI: 0-5.1%). CONCLUSION: Our results indicate that VTEs not related to a vascular catheter are a rare event even in a selected group of severely ill small children considered to be at high risk of VTE. WHAT IS KNOWN: • Children in the PICU often have several risk factors for venous thromboembolism (VTE). • The incidence of VTE in PICU patients is highly uncertain, and there are no evidence-based guidelines regarding VTE prophylaxis. WHAT IS NEW: • This study found an incidence of VTEs not related to a vascular catheter of 0% (95% CI: 0-5.1%). • This indicates that such VTE events are rare even in PICU patients with multiple risk factors for VTE.


Assuntos
Dispositivos de Acesso Vascular , Tromboembolia Venosa , Trombose Venosa , Anticoagulantes/uso terapêutico , Criança , Estado Terminal , Humanos , Incidência , Lactente , Estudos Prospectivos , Fatores de Risco , Dispositivos de Acesso Vascular/efeitos adversos , Tromboembolia Venosa/diagnóstico por imagem , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia , Trombose Venosa/etiologia
6.
Limnol Oceanogr ; 66(3): 827-854, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33888916

RESUMO

The hydrodynamics within small boreal lakes have rarely been studied, yet knowing whether turbulence at the air-water interface and in the water column scales with metrics developed elsewhere is essential for computing metabolism and fluxes of climate-forcing trace gases. We instrumented a humic, 4.7 ha, boreal lake with two meteorological stations, three thermistor arrays, an infrared (IR) camera to quantify surface divergence, obtained turbulence as dissipation rate of turbulent kinetic energy (ε) using an acoustic Doppler velocimeter and a temperature-gradient microstructure profiler, and conducted chamber measurements for short periods to obtain fluxes and gas transfer velocities (k). Near-surface ε varied from 10-8 to 10-6 m2 s-3 for the 0-4 m s-1 winds and followed predictions from Monin-Obukhov similarity theory. The coefficient of eddy diffusivity in the mixed layer was up to 10-3 m2 s-1 on the windiest afternoons, an order of magnitude less other afternoons, and near molecular at deeper depths. The upper thermocline upwelled when Lake numbers (L N ) dropped below four facilitating vertical and horizontal exchange. k computed from a surface renewal model using ε agreed with values from chambers and surface divergence and increased linearly with wind speed. Diurnal thermoclines formed on sunny days when winds were < 3 m s-1, a condition that can lead to elevated near-surface ε and k. Results extend scaling approaches developed in the laboratory and for larger water bodies, illustrate turbulence and k are greater than expected in small wind-sheltered lakes, and provide new equations to quantify fluxes.

7.
Pediatr Crit Care Med ; 22(8): 743-752, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33950886

RESUMO

OBJECTIVES: Pediatric venous thromboembolic events are commonly associated with in situ central venous catheters. The risk for severe venous thromboembolism increases if a larger portion of the vessel lumen is occupied by the central venous catheter. A functioning vascular catheter is required when the continuous renal replacement therapy is used in critically ill children. Due to the high blood flow required for continuous renal replacement therapy, the external diameter of the catheter needs to be larger than a conventional central venous catheter used for venous access, potentially increasing the risk of venous thromboembolism. However, children on continuous renal replacement therapy often receive systemic anticoagulation to prevent filter clotting, possibly also preventing venous thromboembolism. The frequency of catheter-related venous thromboembolic events in this setting has not been described. Our main objective was to determine the prevalence of catheter-related venous thromboembolism in pediatric continuous renal replacement therapy. DESIGN: Retrospective cohort study. SETTING: Tertiary multidisciplinary academic pediatric hospital. PATIENTS: Patients 0-18 years old with a vascular catheter used for continuous renal replacement therapy. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In our series of 80 patients, we used 105 vascular catheters. The median age of the patients was 10 months and PICU mortality rate was 21%. Venous thromboembolic events were considered to be catheter related if located in the same vein as the vascular catheter and radiologically verified. Six (5.7%) catheter-related venous thromboembolic events were found. The clinically relevant complications of venous thromboembolism included superior vena cava syndrome and catheter dysfunction. In one patient, severe and life-threatening pulmonary embolism occurred. In comparison with patients without venous thromboembolism, venous thromboembolic events were associated with lower body weight (p = 0.03) and longer durations of continuous renal replacement therapy (p < 0.01), mechanical ventilation (p = 0.03), and PICU stay (p < 0.01). Five out of six venous thromboembolisms appeared in neonates. CONCLUSIONS: Catheter-related venous thromboembolism is a clinically relevant complication of pediatric continuous renal replacement therapy, with a prevalence of 5.7% in our cohort. Clinicians involved in pediatric continuous renal replacement therapy need to be vigilant for symptoms of venous thromboembolisms and initiate appropriate treatment as soon as possible.


Assuntos
Cateterismo Venoso Central , Cateteres Venosos Centrais , Terapia de Substituição Renal Contínua , Síndrome da Veia Cava Superior , Tromboembolia Venosa , Adolescente , Cateterismo Venoso Central/efeitos adversos , Cateteres Venosos Centrais/efeitos adversos , Criança , Pré-Escolar , Estudos de Coortes , Humanos , Lactente , Recém-Nascido , Prevalência , Terapia de Substituição Renal , Estudos Retrospectivos , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-32944097

RESUMO

BACKGROUND: Targeted surveillance of at-risk individuals in families with increased risk of hereditary cancer is an effective prevention strategy if relatives are identified, informed and enrolled in screening programs. Despite the potential benefits, many eligible at-risk relatives remain uninformed of their cancer risk. This study describes the general public's opinion on disclosure of hereditary colorectal cancer (CRC) risk information, as well as preferences on the source and the mode of information. METHODS: A random sample of the general public was assessed through a Swedish citizen web-panel. Respondents were presented with scenarios of being an at-risk relative in a family that had an estimated increased hereditary risk of CRC; either 10% (moderate) or 70% (high) lifetime risk. A colonoscopy was presented as a preventive measure. Results were analysed to identify significant differences between groups using the Pearson's chi-square (χ2) test. RESULTS: Of 1800 invited participants, 977 completed the survey (54%). In the moderate and high-risk scenarios, 89.2 and 90.6% respectively, would like to receive information about a potential hereditary risk of CRC (χ2, p = .755). The desire to be informed was higher among women (91.5%) than men (87.0%, χ2, p = .044). No significant differences were found when comparing different age groups, educational levels, place of residence and having children or not. The preferred source of risk information was a healthcare professional in both moderate and high-risk scenarios (80.1 and 75.5%). However, 18.1 and 20.1% respectively would prefer to be informed by a family member. Assuming that healthcare professionals disclosed the information, the favoured mode of information was letter and phone (38.4 and 33.2%). CONCLUSIONS: In this study a majority of respondents wanted to be informed about a potential hereditary risk of CRC and preferred healthcare professionals to communicate this information. The two presented levels of CRC lifetime risk did not significantly affect the interest in being informed. Our data offer insights into the needs and preferences of the Swedish population, providing a rationale for developing complementary healthcare-assisted communication pathways to realise the full potential of targeted prevention of hereditary CRC.

9.
Br J Anaesth ; 123(3): 316-324, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31176448

RESUMO

BACKGROUND: Venous thrombosis (VT) in children is often associated with a central venous catheter (CVC). We aimed to determine the incidence of VT associated with percutaneous non-tunnelled CVCs in a general paediatric population, and to identify risk factors for VT in this cohort. METHODS: Observational, prospective study enrolling consecutive patients at a tertiary multi-disciplinary paediatric hospital. A total of 211 percutaneous, non-tunnelled CVCs were analysed. Data regarding potential risk factors for CVC-related VT were collected. Compression ultrasonography with colour Doppler was used to diagnose VT. RESULTS: Overall, 30.3% of children developed CVC-related VT, with an incidence rate of 29.6 (confidence interval, 22.5-36.9) cases/1000 CVC days. Upper body CVC location, multiple lumen CVCs, and male gender were independent risk factors for VT in multivariate analysis. All upper body VTs were in the internal jugular vein (IJV). The occurrence of CVC-related VT did not affect length of paediatric ICU or hospital stay. In patients with VT, femoral CVCs, young age, paediatric ICU admission, and a ratio of CVC/vein diameter >0.33 were associated with VT being symptomatic, occlusive, or both. IJV VT was often asymptomatic and non-occlusive. CONCLUSIONS: Paediatric non-tunnelled CVCs are frequently complicated by VT. Avoiding IJV CVCs and multiple lumen catheters could potentially reduce the overall risk of VT. However, IJV VT was more likely to be smaller and asymptomatic compared with femoral vein VT. More data are needed on the risk of complications from smaller, asymptomatic VT compared with the group of VT with symptoms or vein occlusion. Femoral vein CVCs and CVC/vein diameter >0.33 could be modifiable risk factors for VT with larger thrombotic mass. CLINICAL TRIAL REGISTRATION: ACTRN12615000442505.


Assuntos
Cateteres Venosos Centrais/efeitos adversos , Trombose Venosa/etiologia , Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/métodos , Criança , Pré-Escolar , Feminino , Veia Femoral/diagnóstico por imagem , Humanos , Incidência , Lactente , Veias Jugulares/diagnóstico por imagem , Tempo de Internação/estatística & dados numéricos , Masculino , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais , Suécia/epidemiologia , Ultrassonografia Doppler em Cores , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/epidemiologia
10.
Acta Anaesthesiol Scand ; 63(8): 1028-1036, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31157412

RESUMO

BACKGROUND: Patients with multiple organ failure (MOF) often receive large amounts of resuscitation fluid, making them at high risk of fluid overload (FO). Our main objective was to investigate if the ability to achieve a negative fluid balance during the first 3 continuous renal replacement therapy (CRRT) days was associated with mortality in children with MOF. METHODS: Retrospective cohort study in a tertiary multidisciplinary academic paediatric hospital. The study included 63 patients (age 0-18 years) with 3 or more failing organs receiving CRRT due to acute kidney injury and/or fluid overload. RESULTS: The median age was 4 months, and PICU mortality was 29%. Survivors had significantly lower degree of FO at CRRT initiation, (median 15% (Interquartile range 9-22)) than non-survivors (24% (17%-37%), P = 0.002). On PICU admission, PIM-3 score was significantly higher in non-survivors (P = 0.01), but at CRRT initiation there was no difference in PELOD-2 score (P = 0.98). Mortality in patients achieving a cumulative net negative fluid balance during the first 3 days after CRRT initiation was 12%, compared to 86% in those not achieving this (P < 0.0001). In multivariate analysis, the inability to achieve a net negative fluid balance during 3 days after CRRT initiation (P < 0.0001) and FO >20% at CRRT initiation (P = 0.0019) remained associated with mortality. CONCLUSION: Our results suggest that early fluid removal is associated with improved patient outcome in critically ill children receiving CRRT, and that prompt measures should be taken to prevent fluid overload in critical illness. These results need to be verified in further, prospective studies.


Assuntos
Terapia de Substituição Renal Contínua , Insuficiência de Múltiplos Órgãos/metabolismo , Equilíbrio Hidroeletrolítico , Adolescente , Criança , Pré-Escolar , Terapia de Substituição Renal Contínua/mortalidade , Feminino , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Pediátrica , Masculino , Insuficiência de Múltiplos Órgãos/mortalidade , Análise de Regressão , Estudos Retrospectivos
11.
Proc Natl Acad Sci U S A ; 112(47): 14512-7, 2015 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-26553977

RESUMO

Oceanic uptake of anthropogenic carbon dioxide (CO2) has acidified open-ocean surface waters by 0.1 pH units since preindustrial times. Despite unequivocal evidence of ocean acidification (OA) via open-ocean measurements for the past several decades, it has yet to be documented in near-shore and coral reef environments. A lack of long-term measurements from these environments restricts our understanding of the natural variability and controls of seawater CO2-carbonate chemistry and biogeochemistry, which is essential to make accurate predictions on the effects of future OA on coral reefs. Here, in a 5-y study of the Bermuda coral reef, we show evidence that variations in reef biogeochemical processes drive interannual changes in seawater pH and Ωaragonite that are partly controlled by offshore processes. Rapid acidification events driven by shifts toward increasing net calcification and net heterotrophy were observed during the summers of 2010 and 2011, with the frequency and extent of such events corresponding to increased offshore productivity. These events also coincided with a negative winter North Atlantic Oscillation (NAO) index, which historically has been associated with extensive offshore mixing and greater primary productivity at the Bermuda Atlantic Time-series Study (BATS) site. Our results reveal that coral reefs undergo natural interannual events of rapid acidification due to shifts in reef biogeochemical processes that may be linked to offshore productivity and ultimately controlled by larger-scale climatic and oceanographic processes.


Assuntos
Recifes de Corais , Fenômenos Bioquímicos , Dióxido de Carbono/análise , Clima , Concentração de Íons de Hidrogênio
12.
Environ Microbiol ; 17(10): 3481-99, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24589037

RESUMO

Understanding bacterioplankton community dynamics in coastal hypoxic environments is relevant to global biogeochemistry because coastal hypoxia is increasing worldwide. The temporal dynamics of bacterioplankton communities were analysed throughout the illuminated water column of Devil's Hole, Bermuda during the 6-week annual transition from a strongly stratified water column with suboxic and high-pCO2 bottom waters to a fully mixed and ventilated state during 2008. A suite of culture-independent methods provided a quantitative spatiotemporal characterization of bacterioplankton community changes, including both direct counts and rRNA gene sequencing. During stratification, the surface waters were dominated by the SAR11 clade of Alphaproteobacteria and the cyanobacterium Synechococcus. In the suboxic bottom waters, cells from the order Chlorobiales prevailed, with gene sequences indicating members of the genera Chlorobium and Prosthecochloris--anoxygenic photoautotrophs that utilize sulfide as a source of electrons for photosynthesis. Transitional zones of hypoxia also exhibited elevated levels of methane- and sulfur-oxidizing bacteria relative to the overlying waters. The abundance of both Thaumarcheota and Euryarcheota were elevated in the suboxic bottom waters (> 10(9) cells l(-1)). Following convective mixing, the entire water column returned to a community typical of oxygenated waters, with Euryarcheota only averaging 5% of cells, and Chlorobiales and Thaumarcheota absent.


Assuntos
Alphaproteobacteria/genética , Consórcios Microbianos/genética , Oxigênio/análise , Plâncton/genética , Água do Mar/microbiologia , Synechococcus/genética , Alphaproteobacteria/isolamento & purificação , Bermudas , Dióxido de Carbono/análise , Chlorobi/genética , Chlorobi/isolamento & purificação , Euryarchaeota/isolamento & purificação , Metano/metabolismo , Oxirredução , RNA Ribossômico , RNA Ribossômico 16S/genética , Enxofre/metabolismo , Synechococcus/isolamento & purificação
15.
Proc Natl Acad Sci U S A ; 108(1): 208-13, 2011 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-21173255

RESUMO

Ocean acidification produced by dissolution of anthropogenic carbon dioxide (CO(2)) emissions in seawater has profound consequences for marine ecology and biogeochemistry. The oceans have absorbed one-third of CO(2) emissions over the past two centuries, altering ocean chemistry, reducing seawater pH, and affecting marine animals and phytoplankton in multiple ways. Microbially mediated ocean biogeochemical processes will be pivotal in determining how the earth system responds to global environmental change; however, how they may be altered by ocean acidification is largely unknown. We show here that microbial nitrification rates decreased in every instance when pH was experimentally reduced (by 0.05-0.14) at multiple locations in the Atlantic and Pacific Oceans. Nitrification is a central process in the nitrogen cycle that produces both the greenhouse gas nitrous oxide and oxidized forms of nitrogen used by phytoplankton and other microorganisms in the sea; at the Bermuda Atlantic Time Series and Hawaii Ocean Time-series sites, experimental acidification decreased ammonia oxidation rates by 38% and 36%. Ammonia oxidation rates were also strongly and inversely correlated with pH along a gradient produced in the oligotrophic Sargasso Sea (r(2) = 0.87, P < 0.05). Across all experiments, rates declined by 8-38% in low pH treatments, and the greatest absolute decrease occurred where rates were highest off the California coast. Collectively our results suggest that ocean acidification could reduce nitrification rates by 3-44% within the next few decades, affecting oceanic nitrous oxide production, reducing supplies of oxidized nitrogen in the upper layers of the ocean, and fundamentally altering nitrogen cycling in the sea.


Assuntos
Mudança Climática , Nitrificação/fisiologia , Ciclo do Nitrogênio/fisiologia , Água do Mar/química , Amônia/metabolismo , Dióxido de Carbono/análise , Concentração de Íons de Hidrogênio , Oceanos e Mares , Oxirredução
16.
Int J Pediatr Otorhinolaryngol ; 171: 111632, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37352590

RESUMO

OBJECTIVES: Supraglottoplasty (SGP) for severe laryngomalacia (LM) in children with medical comorbidities has been associated with high risk of surgical failure and increased need of postoperative pediatric intensive care unit (PICU) intervention, but evidence for this is ambiguous. The objective was to evaluate surgical outcome and risk of need for PICU-intervention following SGP for severe LM in comorbid patients. METHODS: Retrospective observational study of 116 patients treated with SGP for severe LM between 2000 and 2021 at a tertial referral pediatric airway surgery center Karolinska University Hospital. Medical records were reviewed and patient data regarding surgical timing, type of SGP procedure, PICU-intervention, complications, and outcomes were recorded. Patients were defined as non-comorbid vs high-risk comorbid (HRC) based on a coexisting comorbidity for risk of surgical failure and postoperative PICU-intervention. Surgical failure was defined as need of revision surgery, tracheostomy or assisted ventilation (continuous positive airway pressure and bilevel positive airway pressure). PICU intervention was defined as need of postoperative assisted ventilation or intubation. Statistical comparisons were performed with outcome of SGP on children with LM and no comorbidities. RESULTS: 41/116 patients included had a HRC associated with an increased risk of PICU-intervention and surgical failure. 75/116 patients were defined as non-comorbid. The overall surgical success in the study population was 89.7% (104/116), 94.7% in the non HRC group vs 80.5% in the HRC-group. 5/41 HRC patients and 1/75 non-comorbid patients needed SGP revision in which 5/6 was successful. There was no significantly increased need for postoperative PICU intervention in HRC patients. CONCLUSION: SGP for severe LM patients with high-risk comorbidities performed in a tertiary setting had an overall good result and low risk of PICU-intervention. Revision SGP was more common in HRC patients but had a good outcome. Multidisciplinary experience in perioperative care of comorbid patients may be of key importance for outcome and children with high-risk comorbidities should thus not be withheld the possible benefit of SGP without assessment at a tertiary pediatric airway center.


Assuntos
Laringomalácia , Humanos , Criança , Lactente , Laringomalácia/cirurgia , Glote/cirurgia , Traqueostomia , Comorbidade , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
17.
Sci Total Environ ; 877: 162860, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36931527

RESUMO

We investigated whether CO2-induced ocean acidification (OA) affects dopamine receptor-dependent behavior in bicolor damselfish (Stegastes partitus). Damselfish were kept in aquaria receiving flow through control (pH ~ 8.03; pCO2 ~ 384 µatm) or OA (pH ~ 7.64; CO2 ~ 1100 µatm) seawater at a rate of 1 L min-1. Despite this relatively fast flow rate, fish respiration further acidified the seawater in both control (pH ~7.88; pCO2 ~ 595 µatm) and OA (pH ~7.55; pCO2 ~ 1450 µatm) fish-holding aquaria. After five days of exposure, damselfish locomotion, boldness, anxiety, and aggression were assessed using a battery of behavioral tests using automated video analysis. Two days later, these tests were repeated following application of the dopamine D1 receptor agonist SKF 38393. OA-exposure induced ceiling anxiety levels that were significantly higher than in control damselfish, and SKF 38393 increased anxiety in control damselfish to a level not significantly different than that of OA-exposed damselfish. Additionally, SKF 38393 decreased locomotion and increased boldness in control damselfish but had no effect in OA-exposed damselfish, suggesting an alteration in activity of dopaminergic pathways that regulate behavior under OA conditions. These results indicate that changes in dopamine D1 receptor function affects fish behavior during exposure to OA. However, subsequent measurements of seawater sampled using syringes during the daytime (~3-4 pm local time) from crevasses in coral reef colonies, which are used as shelter by damselfish, revealed an average pH of 7.73 ± 0.03 and pCO2 of 925.8 ± 62.2 µatm; levels which are comparable to Representative Concentration Pathway (RCP) 8.5 predicted end-of-century mean OA levels in the open ocean. Further studies considering the immediate environmental conditions experienced by fish as well as individual variability and effect size are required to understand potential implications of the observed OA-induced behavioral effects on damselfish fitness in the wild.


Assuntos
Recifes de Corais , Água do Mar , Animais , Dopamina , Dióxido de Carbono/metabolismo , Concentração de Íons de Hidrogênio , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina , Acidificação dos Oceanos , Peixes/metabolismo , Agonistas de Dopamina , Oceanos e Mares
18.
Nat Commun ; 14(1): 7215, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37940668

RESUMO

Coastal upwelling regions are among the most productive marine ecosystems but may be threatened by amplified ocean acidification. Increased acidification is hypothesized to reduce iron bioavailability for phytoplankton thereby expanding iron limitation and impacting primary production. Here we show from community to molecular levels that phytoplankton in an upwelling region respond to short-term acidification exposure with iron uptake pathways and strategies that reduce cellular iron demand. A combined physiological and multi-omics approach was applied to trace metal clean incubations that introduced 1200 ppm CO2 for up to four days. Although variable, molecular-level responses indicate a prioritization of iron uptake pathways that are less hindered by acidification and reductions in iron utilization. Growth, nutrient uptake, and community compositions remained largely unaffected suggesting that these mechanisms may confer short-term resistance to acidification; however, we speculate that cellular iron demand is only temporarily satisfied, and longer-term acidification exposure without increased iron inputs may result in increased iron stress.


Assuntos
Fitoplâncton , Água do Mar , Fitoplâncton/metabolismo , Ecossistema , Concentração de Íons de Hidrogênio , Ferro/metabolismo
19.
J Biophotonics ; 15(7): e202200021, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35452175

RESUMO

Monoclonal antibodies and antibody fragments are increasingly important classes of biotherapeutics. However, these products are both challenging and expensive to manufacture. New process analytical technologies used to monitor these products during their manufacture are of significant interest. Deep UV Raman spectroscopy promises to provide the required specificity and accuracy, however instruments, have historically been large and complex. In this paper, a new deep UV Raman instrument is described using a solid-state laser and a spatial heterodyne spectrometer. The instrument overcomes practical limitations of the technique and could readily be used for online measurement. A series of observations have been made of biopharmaceutical products, including immunoglobulin G and domain antibodies. Where high levels of both specificity and linearity when measuring samples of different concentration with a precision of better than 0.05 mg/mL has been demonstrated.


Assuntos
Produtos Biológicos , Análise Espectral Raman
20.
Cancers (Basel) ; 14(4)2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35205668

RESUMO

PURPOSE: We describe levels of cancer worry in the general population as measured with the Cancer Worry Scale (CWS) and investigate the association with colonoscopy screening intentions in three colorectal cancer risk scenarios. METHODS: The data were sourced through a population-based survey. Respondents (n = 943) completed an eight-item CWS and questions on colonoscopy screening interest at three hypothetical risk levels. RESULTS: Respondents without a personal cancer history (n = 853) scored 9.46 on the six-item CWS (mean, SD 2.72). Mean scores were significantly higher in women (9.91, SD 2.89) as compared to men (9.06, SD 2.49, p < 0.001). Linear regression showed higher cancer worry in women and those with children when controlling for education, age group, and country of birth. High cancer worry (six-item CWS mean >12) was identified in 25% of women and in 17% of men. Among those, 71% would attend a colonoscopy screening compared to 52% of those with low cancer worry (p < 0.001, 5% CRC-risk). CONCLUSIONS: The distribution of cancer worry in a general population sample showed higher mean scores in women, and levels overlapped with earlier findings in cancer-affected samples. Respondents with high cancer worry were more inclined to undergo a colonoscopy screening, and intention increased with higher levels of hypothetical risk.

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